Hello, not sure why it do that, but have you tried to zoom out? Depending on the browser you are using, that option could be in the View menu, and try to zoom out until you can see the whole page and you can zoom in back if it works.
I am not sure about the down key, I would give a try with the Tab key, that should allow you to navigate in the fields until you highlight the Continue button, push Enter when it`s highlighted,
Good luck!
